Additive manufacturing (AM) includes a wide variety of processes of producing an object through the successive layering of material rather than the removal of material. As such, additive manufacturing can create complex geometries without the use of any sort of tools, molds or fixtures, and with little or no waste material. Instead of machining objects from solid billets of material, much of which is cut away and discarded, the only material used in additive manufacturing is what is required to shape the object.
In metal powder additive manufacturing techniques, such as selective laser melting (SLM) and direct metal laser melting (DMLM), metal powder layers are sequentially melted together to form the object. The process takes place in a processing chamber having a precisely controlled atmosphere of inert gas, e.g., argon or nitrogen. Once each layer is created, each two-dimensional slice of the object geometry can be fused by selectively melting the metal powder. The melting may be performed by a high powered laser such as a 100 Watt ytterbium laser to fully weld (melt) the metal powder to form a solid metal. The laser moves in the X-Y direction using scanning mirrors, and has an intensity sufficient to fully weld (melt) the metal powder to form a solid metal. The metal powder bed is lowered for each subsequent two-dimensional layer, and the process repeats until the three-dimensional object is completely formed.
In many additive manufacturing techniques, residual powder may remain on the surface of the resulting 3D object. Any residual powder must be removed prior to any subsequent heat-treatment of the object, e.g., annealing, case hardening, tempering, or precipitation hardening. Heat treating the 3D object without removing the residual powder may alter the geometry of the 3D object.
Current powder removal techniques may require manual manipulation of the 3D object. The 3D object may be large or heavy such that manual manipulation is burdensome. Current powder removal techniques may scatter the powder, into the air and onto the shop floor, resulting in lost or contaminated material. Reclamation of the material may burdensome. Respiration protection may also be required to reduce inhalation and ingestion of the removed powder material.